[tracing] Add SkResourceCache statistics to chrome://tracing (chrome side)

skia/ext/SkDiscardableMemory_chrome.cc

Index: skia/ext/SkDiscardableMemory_chrome.cc
diff --git a/skia/ext/SkDiscardableMemory_chrome.cc b/skia/ext/SkDiscardableMemory_chrome.cc
index 1a98720bf36765f75e04b8899b60fffe0da00d54..30a7f93c836ef7bf22a6106bca290b8502977e24 100644
--- a/skia/ext/SkDiscardableMemory_chrome.cc
+++ b/skia/ext/SkDiscardableMemory_chrome.cc
@@ -26,6 +26,13 @@ SkDiscardableMemoryChrome::SkDiscardableMemoryChrome(
     : discardable_(memory.Pass()) {
 }
 
+base::trace_event::MemoryAllocatorDump*
+SkDiscardableMemoryChrome::CreateMemoryAllocatorDump(
+    const char* name,
+    base::trace_event::ProcessMemoryDump* pmd) const {
+  return discardable_->CreateMemoryAllocatorDump(name, pmd);
+}
+
 SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) {
   return new SkDiscardableMemoryChrome(
       base::DiscardableMemoryAllocator::GetInstance()